CATALYTIC HYDROGENATION OF ISOFLAVONES. THE PREPARATION OF (.+-.)-EQUOL AND RELATED ISOFLAVANS

Hydrogenation of daidzein, or preferably its O,O-diacetyl derivative, gives (±)-equol in good yield only over Pd/C prepared according to the Wessely and Prillinger method, whereas other Pd/C catalysts give mixtures of products. Hydrogenation of O,O,O-triacetylgenistein can be used to prepare isoflavan-4',5,7-triol.